]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
rxrpc: Adjust retransmission backoff
authorDavid Howells <dhowells@redhat.com>
Fri, 21 Jan 2022 23:12:58 +0000 (23:12 +0000)
committerDavid S. Miller <davem@davemloft.net>
Sat, 22 Jan 2022 02:03:24 +0000 (02:03 +0000)
commit2c13c05c5ff4b9fc907b07f7311821910ebaaf8a
tree6250c8fa8747cbf9922ae10e1ce947dea0d3f0ca
parent03c82e80ec283b115c56026ecdb95c901a57c51e
rxrpc: Adjust retransmission backoff

Improve retransmission backoff by only backing off when we retransmit data
packets rather than when we set the lost ack timer.

To this end:

 (1) In rxrpc_resend(), use rxrpc_get_rto_backoff() when setting the
     retransmission timer and only tell it that we are retransmitting if we
     actually have things to retransmit.

     Note that it's possible for the retransmission algorithm to race with
     the processing of a received ACK, so we may see no packets needing
     retransmission.

 (2) In rxrpc_send_data_packet(), don't bump the backoff when setting the
     ack_lost_at timer, as it may then get bumped twice.

With this, when looking at one particular packet, the retransmission
intervals were seen to be 1.5ms, 2ms, 3ms, 5ms, 9ms, 17ms, 33ms, 71ms,
136ms, 264ms, 544ms, 1.088s, 2.1s, 4.2s and 8.3s.

Fixes: c410bf01933e ("rxrpc: Fix the excessive initial retransmission timeout")
Suggested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/164138117069.2023386.17446904856843997127.stgit@warthog.procyon.org.uk/
Signed-off-by: David S. Miller <davem@davemloft.net>
net/rxrpc/call_event.c
net/rxrpc/output.c